Flask



FIG. 1 is a top, rear and left side view showing my new design for a flask.

FIG. 2 is a left side view thereof.

FIG. 3 is a right side view thereof.

FIG. 4 is a front elevation view thereof

FIG. 5 is a rear view thereof

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof. 

CLAIM The ornamental design for a flask, as shown and described. 